Method of creating aligned vias in ultra-high density integrated circuits

Abstract

A method of forming vias aligned with metal lines in an integrated circuit is provided. The method includes: forming a stacked dielectric, capped, hard mask, and first film and photoresist layers; patterning first photoresist layer to provide metal line masks; etching hard mask layer based on patterned first photoresist layer to form metal line masks; ashing first photoresist and film layers; forming second film and photoresist layers on hard mask layer; patterning second photoresist layer to form via masks across opposing sides of metal line masks; etching second film and capped layers based on patterned second photoresist layer; ashing second photoresist and film layers; etching dielectric and capped layers based on a pattern of hard mask layer to provide via and metal line regions; etching hard mask and capped layers; and performing dual damascene process operations to form vias and metal lines in via and metal line regions.